C5aR inhibitors for use in the treatment of chemotherapy-induced iatrogenic pain

1. A method of preventing and/or treating chemotherapy-induced iatrogenic pain (CIIP), the method comprising administering a therapeutically effective amount of a C5aR inhibitor to a subject undergoing chemotherapy, wherein the C5aR inhibitor is a compound of formula (II)

or a pharmaceutically acceptable salt thereof, wherein

X is a heteroatom selected from the group consisting of

S, O and N;

Y is selected from the group consisting of:

hydrogen, halogen, linear or branched C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkoxy, hydroxy,—COOH, C 1 -C 4 -acyloxy, phenoxy, cyano, nitro,—NH 2 , C 1 -C 4 -acylamino, halo-C 1 -C 3 -alkyl, benzoyl, linear or branched C 1 -C 5 -alkanesulfonate, linear or branched C 1 -C 5 -alkanesulfonamides, and linear or branched C 1 -C 8 -alkyl sulfonylmethyl;

Z is an unsubstituted tetrazole or a heteroaryl ring selected from the group consisting of:

triazole, pyrazole, oxazole, thiazole, isooxazole, isothiazole, thiadiazole and oxadiazole, wherein the heteroaryl ring is substituted by one hydroxy group, and wherein the heteroaryl ring is optionally further substituted by one or more groups selected from the group consisting of halogen, linear or branched C 1 -C 4 -alkyl, C 2 -C 4 -alkenyl, C 1 -C 4 -alkylamino, C 1 -C 4 -alkoxy, C 1 -C 4 -alkylthio, C 1 -C 4 -acyloxy, cyano, nitro, NH 2 , C 1 -C 4 -acylamino, halo-C 1 -C 3 -alkyl, halo-C 1 -C 3 -alkoxy, linear or branched C 1 -C 5 -alkanesulfonate and linear or branched C 1 -C 5 -alkanesulfonamides,

and wherein the C5aR inhibitor is administered orally.

2. The method according to claim 1 , wherein the chemotherapy-induced iatrogenic pain is allodynia.

3. The method according to claim 1 , wherein:

X is a heteroatom selected from the group consisting of

S and O;

Y is selected from the group consisting of:

hydrogen, halogen, linear or branched C 1 -C 4 -alkyl and halo-C 1 -C 3 -alkyl;

Z is an unsubstituted tetrazole or a heteroaryl ring selected from the group consisting of:

triazole, pyrazole, isooxazole, isothiazole, thiadiazole and oxadiazole, wherein the heteroaryl ring is substituted by one hydroxy group, and wherein the heteroaryl ring is optionally further substituted by one or more groups selected from the group consisting of halogen, linear or branched C 1 -C 4 -alkyl, C 1 -C 4 -alkylthio, and halo-C 1 -C 3 -alkyl.

4. The method according to claim 3 , wherein:

Y is selected from the group consisting of hydrogen, trifluoromethyl, chlorine, methyl and t-butyl.

5. The method according to claim 3 , wherein:

Z is an unsubstituted tetrazole or a heteroaryl ring selected from the group consisting of:

triazole, pyrazole, isooxazole, isothiazole, thiadiazole and oxadiazole, wherein the heteroaryl ring is substituted by one hydroxy group and wherein the heteroaryl ring is optionally further substituted by one or more groups selected from the group consisting of methyl, trifluoromethyl and chlorine.

6. The method according to claim 1 , wherein the C5aR inhibitor is selected from the group consisting of:

N-{4-[(1R)-1-(1H-tetrazol-5-yl)ethyl]phenyl}-4-(trifluoromethyl)-1,3-thiazol-2-amine;

4-methyl-N-{4-[(1R)-1-(1H-tetrazol-5-yl)ethyl]phenyl}-1,3-thiazol-2-amine;

4-tert-butyl-N-{4-[(1R)-1-(1H-tetrazol-5-yl)ethyl]phenyl}-1,3-thiazol-2-amine;

N-{4-[(1R)-1-(1H-tetrazol-5-yl)ethyl]phenyl}-1,3-thiazol-2-amine;

N-{4-[(1R)-1-(1H-tetrazol-5-yl)ethyl]phenyl}-4-(trifluoromethyl)-1,3-oxazol-2-amine;

4-methyl-N-{4-[(1R)-1-(TH tetrazol-5-yl)ethyl]phenyl}-1,3-oxazol-2-amine;

5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1H pyrazol-1-ol;

4-methyl-5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1H-pyrazol-1-ol;

5-[(1R)-1-(4-([4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1H-1,2,3-triazol-1-ol;

5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl] isoxazol-3-ol;

4-methyl-5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]isoxazol-3-ol;

5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl] isothiazol-3-ol;

4-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1,2,5-oxadiazol-3-ol;

4-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1,2,5-thiadiazol-3-ol; and

5-[(1R)-1-(4-{[4-(trifluoromethyl)-1,3-thiazol-2-yl]amino}phenyl)ethyl]-1H 1,2,4-triazol-1-ol.

7. The method according to claim 1 , wherein the chemotherapy-induced iatrogenic pain is induced by a chemotherapeutic agent selected from the group consisting of platinum based drugs, taxanes, epothilones, plant alkaloids, thalidomide, lenalidomide and pomalidomide, carfilzomib, bortezomib and eribulin.

8. The method according to claim 7 , wherein the chemotherapeutic agent is selected from the group consisting of cisplatin, carboplatin, oxaliplatin, paclitaxel, cabazitaxel, docetaxel, ixabepilone, vinblastine, vincristine, vinorelbine, etoposide, thalidomide, lenalidomide, pomalidomide, carfilzomib, bortezomib and eribulin.

9. The method according to claim 7 , wherein the chemotherapeutic agent is selected from taxanes and platinum based drugs.

10. The method according to claim 8 , wherein the chemotherapeutic agent is paclitaxel.

11. The method according to claim 1 , wherein the C5aR inhibitor is administered as a pharmaceutical composition comprising the C5aR inhibitor and at least a pharmaceutically acceptable excipient.